While much of the economy continues to sputter, the median growth rate of 2013 Inc. 5000 companies is an impressive 142 percent. The companies on this year’s list report have created over 520,000 jobs in the past three years, and aggregate revenue among the honorees reached $241 billion.

“Not all the companies in the Inc. 500 | 5000 are in glamorous industries, but in their fields they are as famous as household name companies simply by virtue of being great at what they do. They are the hidden champions of job growth and innovation, the real muscle of the American economy,” said Inc. Editor Eric Schurenberg in a prepared statement.

Email has always been about doing the dirty work of digital, being the unsung hero, and not minding the spotlight wandering over to less productive yet sexier marketing tools. Email’s role in the economy is indisputable and 2013 was a banner year.

The blog Email Expert compiled a list of email-related companies that made the Inc. 5000 of which I have referenced in this column. I took out their top one and number 15 on the Inc. 5000 list, LivingSocial, as it certainly leverages email in a significant fashion but is not an email company from my view. I view an email marketing company as one that primarily sells email marketing products and/or services.

This leaves us with 11 companies that cover a wide range of the email marketing ecosystem. (Disclosure: my company, BrightWave Marketing, is on the list.)

Sailthru – New York, NY #30

LiveIntent – New York, NY #71

Act-On Software – Beaverton, OR #172

Marketo – San Mateo, CA #367

Bronto Software – Durham, NC #1702

BrightWave Marketing #1762

Net Atlantic #2097

Infusionsoft – Chandler, AZ #2296

ClickMail Marketing – San Mateo, CA #2304

Message Systems – Columbia, MD #3194

Delivra – Indianapolis, IN #4592

These 11 companies had approximately $186.8 million in combined 2012 revenue and created approximately 955 jobs during the previous three years (according to Inc. statistics). Not bad – not bad at all.

The following are four publicly held companies that rely on selling email marketing in a significant fashion. Marketo, as a marketing automation company, places a large emphasis on email and from my opinion, email is the central marketing piece to marketing automation, so therefore I included it. It is also the one company included in the Inc. 5000 list that is now publicly traded. There are several large email companies that are smaller subsidiaries of their parent company and they are not included since they don’t break out email-specific revenue in their filings.

Constant Contact. The small business software company has a market cap of $596 million and 1,162 employees.

Lyris. The company has 162 employees with a market cap of almost $17 million.

Marketo. Riding the marketing automation wave, the company has a $1.3 billion market cap and 339 employees.

Responsys. The company has a $721 million market cap with 996 employees. This is an impressive increase from last year on both fronts.

(Market caps are as of September 3, 2013 and public company data from Yahoo Finance).

Notably ExactTarget is no longer on the list due to being acquired by Salesforce.com. I would expect the publicly traded companies list to look much different next year with acquisitions continually reshaping the landscape and also the possibility of several email companies going public in the next year.

The employees, partners, clients, and vendors who work with these 15 companies all play varying roles in the continued growth of the email marketing sector. It is as thriving as ever and these 15 companies should be proud in the greater role they play in job creation, driving ROI for clients, and overall positive impact in each of their communities.